A twelve-phase permanent magnet motor control method based on rotating shaft system position observation
By equating the twelve-phase permanent magnet synchronous motor to four three-phase control units, designing a rotating shaft system observer and adopting a master-slave control method, high-precision sensorless control of the twelve-phase high-speed permanent magnet synchronous motor is achieved, solving the problem of insufficient observation accuracy at high speeds, resulting in smooth dynamic response and expanding the stable operating range of the motor.
Patent Information
- Application Number
- CN202610183114.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-09
- Publication Date
- 2026-06-23
AI Technical Summary
Existing technologies make it difficult to achieve high-precision sensorless rotor position and speed observation in twelve-phase high-speed permanent magnet synchronous motors, especially under high speed and nonlinear coupling characteristics, the observation accuracy of traditional methods is difficult to meet the requirements.
The twelve-phase permanent magnet synchronous motor is equivalent to four independent three-phase control units. A rotor position observer based on the rotating shaft system is designed. The rotor position and speed signals are extracted from the back electromotive force through a phase-locked loop. The master controller is selected as the final observation result of the system using a master-slave control method and input to the dual closed-loop vector control system.
It achieves high-precision sensorless control of a twelve-phase high-speed permanent magnet synchronous motor under low carrier ratio conditions, with stable dynamic response, strong anti-interference ability, and widens the stable operating range of the motor, avoiding observation instability problems.
Smart Images
Figure CN122268220A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of motor control technology, and in particular to a control method for a twelve-phase permanent magnet motor based on the observation of the position of the rotating shaft system. Background Technology
[0002] Twelve-phase high-speed permanent magnet synchronous motors (PMSMs) offer advantages such as high power density and high efficiency. Their stator employs four sets of spatially symmetrical three-phase windings, driven by four independent three-phase inverter units, thus providing strong fault-tolerant operation capabilities. This is crucial for fields with extremely high reliability requirements, such as marine propulsion and aerospace. To achieve high-performance vector control, accurately acquiring rotor position and speed is essential. Traditional methods typically involve directly measuring rotor position by installing mechanical position sensors (such as encoders or resolvers) on the motor shaft. However, for high-speed PMSMs, installing mechanical sensors is difficult, increasing system cost, complexity, and failure rate. Furthermore, at extremely high speeds, the reliability and lifespan of the sensors face challenges. Therefore, sensorless control technology has become a key research focus in the control of high-speed PMSMs.
[0003] Due to the unique configuration of the stator windings of a 12-phase permanent magnet synchronous motor (PMSM), its mathematical model, in the natural coordinate system, represents a high-order inductance matrix. The self-inductance and mutual inductance between each phase winding exhibit strong nonlinear coupling characteristics, making it difficult for the rotor position observation methods applicable to general three-phase PMSMs to meet the technical requirements in the control system of a 12-phase high-speed PMSM. Therefore, researching sensorless control technology suitable for 12-phase high-speed PMSMs is of great significance for realizing a high-performance, high-efficiency dual-closed-loop vector control system for PMSMs. Summary of the Invention
[0004] The purpose of this invention is to overcome the shortcomings of the prior art and propose a control method for a twelve-phase permanent magnet motor based on the observation of the position of a rotating axis system. The observer based on the rotating coordinate system has better parameter design and is more stable in low carrier ratio control.
[0005] The technical problem solved by this invention is achieved through the following technical solution: A control method for a twelve-phase permanent magnet motor based on the position observation of a rotating shaft system includes the following steps: Step 1: Based on the dq axis coefficient mathematical model of the twelve-phase permanent magnet synchronous motor, establish an equivalent three-phase permanent magnet synchronous motor steady-state mathematical model, and control the twelve-phase permanent magnet synchronous motor by equivalently controlling it with four independent three-phase motor control units; Step 2: Construct a rotor position observer based on a rotating shaft system for each control unit. Design the observer parameters according to the steady-state mathematical model of the equivalent three-phase permanent magnet synchronous motor, and use the observer to observe the back electromotive force of the motor. Step 3: Calculate the rotor position error based on the back EMF observation results of the observer, input the error to the corresponding phase-locked loop, and obtain the rotor position and speed signals corresponding to each control unit; Step 4: According to the master-slave control method, select one of the four control units as the master controller, and use the rotor position and speed signal corresponding to the master controller as the final observation result of the system. Step 5: The final observation results of rotor position and speed are used as feedback signals and input to the dual closed-loop vector control system of the twelve-phase permanent magnet synchronous motor to realize sensorless control of the twelve-phase high-speed permanent magnet synchronous motor.
[0006] Furthermore, the dq-axis coefficient mathematical model of the twelve-phase permanent magnet synchronous motor in step 1 includes voltage equations and flux linkage equations: , in, The voltage across the dq axis. Let dq be the current in the axis system. For the dq axis magnetic flux linkage, It is a permanent magnet flux chain. R s For stator resistance, ω e The rotor's electric angular velocity, The dq axis cross-coupling matrix; Let be the inductance matrix of the dq axis system.
[0007] Furthermore, the equivalent steady-state mathematical model of the three-phase permanent magnet synchronous motor in step 1 is as follows: in, u dk , u qk , i dk , i qk For the first k The dq axis voltage and current of each control unit R s For stator resistance, L Dk and L Qk For the first k The equivalent dq-axis inductance of each control unit It is a permanent magnet flux linkage.
[0008] Furthermore, the rotor position observer in step 2 is: in, and For the first k Observed values of dq axis current for each control unit and For the first k Observed back electromotive force values of the dq axis of each control unit. A c , B c The coefficient matrix, u dk , u qk , i dk , i qk For the first k The dq axis voltage and current of each control unit, where G is the observer parameter. L Dk and L Qk For the first k The equivalent dq-axis inductance of each control unit.
[0009] Furthermore, the observer parameters in step 2 are: in, For the damping ratio of the target second-order system, The bandwidth of the target system.
[0010] Furthermore, the rotor position error in step 3 is: in, and For the first k Observed back electromotive force values of the dq axis of each control unit.
[0011] Furthermore, the observed rotor position and rotational speed values in step 3 are: in, K p and K i For PI controller parameters, and For the first k The rotor position and speed observed by each control unit.
[0012] Furthermore, the master-slave control method in step 4 is as follows: in, i dck Indicates the first k DC bus current of each control unit and The rotor position and speed observed by the control unit with the largest DC bus current. and This represents the final observed results of rotor position and speed. These final observed results are used as feedback signals and input to the dual closed-loop vector control system of the twelve-phase permanent magnet synchronous motor, achieving sensorless control of the twelve-phase high-speed permanent magnet synchronous motor. The advantages and positive effects of this invention are: This invention equates a twelve-phase permanent magnet synchronous motor to four three-phase control units. A state observer based on a rotating coordinate system is designed for each unit to observe the back electromotive force (EMF). The rotor position and speed signals of each unit are extracted from the back EMF via a phase-locked loop (PLL). According to a master-slave control method, one of the four control units is selected as the master controller, and the rotor position and speed signals corresponding to that master controller are used as the final observation results of the system. These are then used as feedback signals and input to the dual closed-loop vector control system of the twelve-phase permanent magnet synchronous motor, achieving sensorless control of the twelve-phase high-speed permanent magnet synchronous motor. The rotor position observer based on a rotating coordinate system described in this invention maintains good tracking performance even when the motor is running at high speed, especially under low carrier ratio conditions. Compared to a stationary coordinate system observer, it has stronger anti-interference capabilities, smoother dynamic response, effectively avoids observation instability caused by switching frequency limitations, broadens the stable operating range of the motor, and achieves high-precision closed-loop control of the twelve-phase high-speed permanent magnet synchronous motor. Attached Figure Description
[0013] Figure 1 This is a block diagram of the sensor control system for a twelve-phase high-speed permanent magnet synchronous motor as described in this invention. Figure 2 This is a block diagram of the rotating shaft system position observer structure described in this invention; Figure 3 This is a block diagram of the phase-locked loop structure described in this invention; Figure 4 The simulation waveforms are for the starting-generating control of a twelve-phase high-speed permanent magnet synchronous motor when the present invention is used. Detailed Implementation
[0014] The present invention will be further described in detail below with reference to the accompanying drawings.
[0015] Figure 1 The system mainly includes dual-loop vector control, a rotor position observer based on the rotating shaft system, and a master-slave controller. The dual-loop vector control system comprises an outer speed loop and an inner current loop. The outer speed loop obtains a reference current based on the difference between the given speed and the observed speed. The inner current loop obtains the voltage signal required for motor control based on the difference between the reference current and the sampled current, and modulates it through an SVPWM module before sending the modulated signal to the inverter to achieve motor control. The rotor position observer, based on the motor voltage and current signals under the rotating shaft system and combined with the motor's mathematical model, observes the motor's back electromotive force in real time and calculates the motor's rotor position and speed through a phase-locked loop. The master-slave controller compares the magnitude of the DC bus current in each control unit, selecting the control unit with the largest current as the master control unit. The observation result of the rotor position observer of that control unit is used as the feedback signal of the dual-loop vector control system, thereby realizing sensorless control of a twelve-phase high-speed permanent magnet synchronous motor.
[0016] A control method for a twelve-phase permanent magnet motor based on the position observation of a rotating shaft system includes the following steps: Step 1: Based on the dq axis coefficient mathematical model of the twelve-phase permanent magnet synchronous motor, establish an equivalent three-phase permanent magnet synchronous motor steady-state mathematical model, and control the twelve-phase permanent magnet synchronous motor by equivalently controlling it with four independent three-phase motor control units.
[0017] The dq-axis mathematical model of the twelve-phase permanent magnet synchronous motor in step 1 includes voltage equations and flux linkage equations: , in, The voltage across the dq axis. Let dq be the current in the axis system. For the dq axis magnetic flux linkage, It is a permanent magnet flux chain. R s For stator resistance, ω e The rotor's electric angular velocity, The dq axis cross-coupling matrix; Let be the inductance matrix of the dq axis system.
[0018] The steady-state mathematical model of the equivalent three-phase permanent magnet synchronous motor in Step 1 is as follows: in, u dk , u qk , i dk ,i qk For the first k The dq axis voltage and current of each control unit R s For stator resistance, L Dk and L Qk For the first k The equivalent dq-axis inductance of each control unit It is a permanent magnet flux linkage.
[0019] Step 2: Construct a rotor position observer based on a rotating shaft system for each control unit. Design the observer parameters according to the steady-state mathematical model of the equivalent three-phase permanent magnet synchronous motor, and use the observer to observe the back electromotive force of the motor.
[0020] The rotor position observer structure in step 2 is as follows: Figure 2 As shown, its structure is as follows: in, and For the first k Observed values of dq axis current for each control unit and For the first k Observed back electromotive force values of the dq axis of each control unit. A c , B c The coefficient matrix, u dk , u qk , i dk , i qk For the first k The dq axis voltage and current of each control unit, where G is the observer parameter. L Dk and L Qk For the first k The equivalent dq-axis inductance of each control unit.
[0021] The observer parameters in step 2 are: in, For the damping ratio of the target second-order system, The bandwidth of the target system.
[0022] Step 3: Calculate the rotor position error based on the back EMF observation results of the observer, input the error to the corresponding phase-locked loop, and obtain the rotor position and speed signals corresponding to each control unit.
[0023] The rotor position error in step 3 is: in, and For the first k Observed back electromotive force values of the dq axis of each control unit.
[0024] The phase-locked loop structure in step 3 is as follows: Figure 3 As shown, the observed rotor position and speed values are: in, K p and K i For PI controller parameters, and For the first k The rotor position and speed observed by each control unit.
[0025] Step 4: According to the master-slave control method, select one of the four control units as the master controller, and use the rotor position and speed signal corresponding to the master controller as the final observation result of the system.
[0026] The master-slave control method in step 4 is as follows: in, i dck Indicates the first k DC bus current of each control unit and The rotor position and speed observed by the control unit with the largest DC bus current. and This represents the final observed results of rotor position and rotational speed.
[0027] Step 5: The final observation results of rotor position and speed are used as feedback signals and input to the dual closed-loop vector control system of the twelve-phase permanent magnet synchronous motor to realize sensorless control of the twelve-phase high-speed permanent magnet synchronous motor.
[0028] Based on the above-mentioned control method for a twelve-phase permanent magnet motor based on the position observation of a rotating shaft system, the effectiveness of the invention is verified by simulation using a twelve-phase high-speed permanent magnet synchronous motor.
[0029] The main parameters of the motor are: rated current 1600 A, rated torque 920 N∙m, rated speed 21000 r / min, stator resistance 0.002 Ω, d-axis inductance 97 μH, q-axis inductance 106 μH, number of pole pairs 2, and rotor flux linkage 0.107 Wb.
[0030] Figure 4 The simulation waveforms show the start-up and generation control of a twelve-phase high-speed permanent magnet synchronous motor using the method of this invention. The motor enters the generation state when it reaches 18000 r / min. The rated load is applied at 2.5s, and 1.33 times the rated load is applied at 3s. It can be seen that the rotor position observation error is consistently less than 5 degrees, and the control system can achieve stable control under different load conditions.
[0031] It should be emphasized that the embodiments described in this invention are illustrative rather than limiting. Therefore, this invention includes, but is not limited to, the embodiments described in the specific implementation. Any other implementations derived by those skilled in the art based on the technical solutions of this invention are also within the scope of protection of this invention.
Claims
1. A control method for a twelve-phase permanent magnet motor based on the position observation of a rotating shaft system, characterized in that: Includes the following steps: Step 1: Based on the dq axis coefficient mathematical model of the twelve-phase permanent magnet synchronous motor, establish an equivalent three-phase permanent magnet synchronous motor steady-state mathematical model, and control the twelve-phase permanent magnet synchronous motor by equivalently controlling it with four independent three-phase motor control units; Step 2: Construct a rotor position observer based on a rotating shaft system for each control unit. Design the observer parameters according to the steady-state mathematical model of the equivalent three-phase permanent magnet synchronous motor, and use the observer to observe the back electromotive force of the motor. Step 3: Calculate the rotor position error based on the back EMF observation results of the observer, input the error to the corresponding phase-locked loop, and obtain the rotor position and speed signals corresponding to each control unit; Step 4: According to the master-slave control method, select one of the four control units as the master controller, and use the rotor position and speed signal corresponding to the master controller as the final observation result of the system. Step 5: The final observation results of rotor position and speed are used as feedback signals and input to the dual closed-loop vector control system of the twelve-phase permanent magnet synchronous motor to realize sensorless control of the twelve-phase high-speed permanent magnet synchronous motor.
2. The control method for a twelve-phase permanent magnet motor based on the position observation of a rotating shaft system according to claim 1, characterized in that: The dq-axis mathematical model of the twelve-phase permanent magnet synchronous motor in step 1 includes voltage equations and flux linkage equations: ； ； in, The voltage across the dq axis. Let dq be the current in the axis system. For the dq axis magnetic flux linkage, It is a permanent magnet flux chain. R s For stator resistance, ω e The rotor's electric angular velocity, The dq axis cross-coupling matrix; Let be the inductance matrix of the dq axis system.
3. The control method for a twelve-phase permanent magnet motor based on the position observation of a rotating shaft system according to claim 1, characterized in that: The steady-state mathematical model of the equivalent three-phase permanent magnet synchronous motor in step 1 is as follows: ； in, u dk , u qk , i dk , i qk For the first k The dq axis voltage and current of each control unit R s For stator resistance, L Dk and L Qk For the first k The equivalent dq-axis inductance of each control unit It is a permanent magnet flux linkage.
4. The control method for a twelve-phase permanent magnet motor based on the position observation of a rotating shaft system according to claim 1, characterized in that: The rotor position observer in step 2 is: ； ； ； in, and For the first k Observed values of dq axis current for each control unit and For the first k Observed back electromotive force values of the dq axis of each control unit. A c , B c The coefficient matrix, u dk , u qk , i dk , i qk For the first k The dq axis voltage and current of each control unit, where G is the observer parameter. L Dk and L Qk For the first k The equivalent dq-axis inductance of each control unit.
5. The control method for a twelve-phase permanent magnet motor based on the position observation of a rotating shaft system according to claim 4, characterized in that: The observer parameters in step 2 are: ； in, For the damping ratio of the target second-order system, The bandwidth of the target system.
6. The control method for a twelve-phase permanent magnet motor based on the position observation of a rotating shaft system according to claim 1, characterized in that: The rotor position error in step 3 is: ； in, and For the first k Observed back electromotive force values of the dq axis of each control unit.
7. The control method for a twelve-phase permanent magnet motor based on the position observation of a rotating shaft system according to claim 1, characterized in that: The observed values of rotor position and rotational speed in step 3 are: ； in, K p and K i For PI controller parameters, and For the first k The rotor position and speed observed by each control unit.
8. The control method for a twelve-phase permanent magnet motor based on the position observation of a rotating shaft system according to claim 1, characterized in that: The master-slave control method in step 4 is as follows: ； ； in, i dck Indicates the first k DC bus current of each control unit and The rotor position and speed observed by the control unit with the largest DC bus current. and The final observed results of rotor position and speed are used as feedback signals and input to the dual closed-loop vector control system of the twelve-phase permanent magnet synchronous motor to realize sensorless control of the twelve-phase high-speed permanent magnet synchronous motor.